Apparatus for the treatment of immiscible liquids



NOV. 26, 1.935. A, KRAMER 2,022,205

APPARATUS FOR THE TREATMENT OF IMMISCIBLE LIQUIDS Original Filed July20, 195i 2 Sheets-Sheet 1 FIG. l I

'G. A. KRAMER 2,022,205

APPARATUS FOR THE TREATIVIENIQE IMMISCIBLEE LIQUIDS Nov. 26, 1935.

Original Filed July 20, 1951 2 Sheets-Sheet 2 Fla. 5

F'se. A.-

Patented Nov. 26, 1935 UNITED STATES PATENT OFFICE APPARATUS FOR THETREATMENT IMMIISCIBLE LIQUIDS Gustav A. Kramer, New York, N. Y.,assignor to Shell Development Company, San Francisco, Calif., acorporation of Delaware Original-application July 20, 1931, Serial No.

551,970. Divided and this application February 28, 1934, Serial No.713,359. In Canada September 21, 1931 6 Claims.

This invention relates to a novel apparatus for contacting immiscibleliquids with each other for the purpose of extraction, chemicaltreatment or the like, and more particularly to an apparatus wherein itis desired to carry out s ch contact in countercurrent relationship ofthe W liquids.

The preferred operation comprises passing two substantially immiscibleliquids in countercurrent flow to each other through a pluralityofstages arranged in contiguous relationship and communicating with eachat a plurality of points, each alternate stage containing an agitatingmeans, the end stages being characterized as quiescent or separatingzones and each end stage containing an inlet and outletior the liquidsundergoing marks, therefore, reference will now be immediately had tothe accompanying drawings, generally illustrating at least one practicalembodiment of a novel systematic combination of means for carrying forththe steps of the method involved, although not essentially the onlyapparatus for doing so, in which drawings Fig. l is a sectional sideelevation of the apparatus carried out according to this invention;

Fig. 2 is a front elevation of a diaphragm;

Fig. 3 is a rear elevation of a diaphragm;

Fig. 4 is a plan view of a diaphragm closing piece and Fig. 4a is an endview of the diaphragm closing piece.

In the drawings, wherein like characters ofreference designatecorresponding parts throughout the several views: it is a cylindricalshell provided with removable covers M and i2 and with,

an outer jacket 63 which may be utilized for heating or cooling theliquids in the mixer, should this be necessary. it is a shaft runningparallel to the center line of shell to but preferably eccentricallylocated therein and supported in bearings 2i. Stumng glands 22 preventleakage of liquids along the shaft when in motion, and specially formedend or ends of the shaft as shown at 23 permit connection to a primemover by ,means of pulleys or couplings or the like. The

shaft carries within the-space enclosed by vesselto, suitably spacedrotors it of any desired numher which when revolving, agitate the liquidcontained in the mixing device, causing intermingling of otherwise notmiscible liquids in more or less fine emulsions. Diaphragms 25' are sospacedthat one pair of them; form a substantially enclosed space 26 inwhich the agitation of rotors 26 is not felt and lsof such size that theemulsions formed in the mixing compartments may separate due todifferences in specific gravity of the liquids in question.

Such diaphragms may be also placed between each end rotor and end platesH and 82 of the mixing vessel, or they may be omitted and externalseparating vessels substituted for this purpose. 1

The diaphragms 25 are closed on shaft by means of diaphragm closingpiece 3tv which permits rotation of the shaft without substantialleakage of fluids between compartments.

The agitating and separating stages are in 20 communication throughopenings 2? suitably placed near the upper and lower peripheries of thediaphragms and of such a size that they permit liquid to circulatebetween the two stages without causing the turbulence of the mixing pzones to be communicated to the separating zones. Vanes 3d tend toincrease the turbulence and eddy flow in the agitating compartmentswhereas vanes 35 tend to straighten out eddy flow in the separatingcompartments thereby expedit- 30 ing' Stratification of the immisciblefluids. Openings 28, 2t, 3t and it are provided for feeding into anddischarging from the vessel it, the materials to be interacted, whileopenings 32 may be provided for sampling the liquids at various-steps 35of the process. Coil 333 may be provided for ad-' ditional internalcooling, either by water .or byother refrigerating media or may beutilized for heating purposes, if so desired, by the passagetherethrough of hot water, steam or other heating media.

The operation of the device may possibly be best understood by firstconsidering the rotorsat rest and supposing that two immiscible liquidsof different specific gravities, e. g., sulfuric acid and hydrocarbonoil have been placed into the apparatus so that practically the entirespace within the shell W is filled with liquid. The two liquids willnaturally rest in the device in such a manner that the heavier oneoccupies a lower layer, the lighter one resting on top as, for example,shown by the dividing line drawn in Fig. 1.

It now the rotors are set in motion, the two liquids in the mixingcompartments will be emulsified, but no substantial disturbance of theseparated liquids occurs in the separating compartments because thetotal hydraulic head acting on openings 21 from the mixing compartment15 still the same as that from the neighboring separating compartment;If we now remove some of the heavy liquid through opening 3i, thedeficiency will be made up by additional liquid flowing in through theopenings of diaphragm 25. However, this incoming liquid contains notonly sulfuric acid, but also admixed hydrocarbon, so that afterseparation of the two, the level of sulfuric acid in this compartmentwill be lower than that corresponding to the hydraulic head necessary tomaintain equilibrium. Consequently, some additional liquid will flowinto this separating comparment through the lower openings of thediaphragm 25 and some hydrocarbon through the upper openings of thediaphragm 25 back into the. neighboring mixing compartment, until byseparation of the incoming emulsion, sufficient acid has beenaccumulated to again establish equilibrium. Similarly, if theequilibrium were disturbed by feeding some additional acid into theopening 29, this acid will again disturb the hydraulic equilibrium andwill force more acid through the. lower openings of the neighboringdiaphragm and so on through the entire device until equilibrium hasagain been reached;

, By the same way, additional hydrocarbon fed into opening 30 wouldagain be gradually distributed through the entire system, meanwhilebeing successively agitated with acid by the rotors in the mixingchambers.

If hydrocarbon is fed continuously into opening 30 and is beingcontinuously removed at the same rate through opening 28, at the sametime acid is being fed into nozzle 29 and being removed at the same ratethrough nozzle 3|, it is easily understood that while the dividinglevels in the separating compartments remain substantially unchanged,the acid and hydrocarbon come into thorough contact with each other incountercurrent, fresh acid always being contacted with nearly fullytreated hydrocarbon and untreated hydrocarbon with nearly fully spentacid.

The relative time of contact may be varied independent of thethroughput. Assume the volumetric capacity of the shell to be 200gallons and that it contains 100 gallons of each liquid, the hourly feedalso being 100 gallons of each. The average contact time of each of theliquids will then be one hour. If the contents of the shell are changedto 50 gallons of the light liquid and 150 gallons of the heavy liquid,the throughput being kept at 100 gallons per hour for each of theliquids, then the average contact time for the light liquid will bereduced to one-half hour and that for the heavy liquid increased to oneand onehalf hours; the ratio of the contact. times of the two liquidsthereby decreasing from 1 to In similar manner, the relative time ofcontact of the light or heavy liquid may be either increased ordecreased, depending on'the character of the substantially immiscibleliquids and the economic conditions of operation.

Under certain circumstances, it may be desirable to effect the contactof the two substantially immiscible fluids by means 01 parallel flow, inwhich case the lighter fluid is introduced at 30 and removed at the samerate through 28, while the heavier fluid is fed. in at 3| and removed atthe same rate through 29.

The number of agitating and settling chambers employed is dependent ,onthe character of the liquids undergoing treatment and the nature of theprocess. For example, in parallel flow, an agitating chamberincommunication with two settling chambers may suffice whereas incountercurrent flow a plurality of agitating chambers is desirable, theefiiciency of the process increasing with the number of agitatingcompartments.'

If the volumetric capacity of any of the end settling zones isinsufficient to permit a well defined separation to take place, but.instead an emulsified mass is present, stratification of said emulsifiedmass can be caused to take place by introducing said mass into one ormore auxiliary surge tanks which, for all practical purposes, serve tocompensate for the inadequate volumetric capacity of any end settlingzone. The auxiliary tank or tanks may thus be regarded as comprisingpart of the end settling zone or zones.

By way of example, only, reference will be had to the treatment of amineral oil fraction consisting essentially of hydrocarbons containingfour carbon atoms to the molecule with sulfuric acid of such strengththat the tertiary-base olefines contained therein, such'as isobutylene,are selectively absorbed by the sulfuric acid and removed therewith,although it is to be understood that the process and apparatus isapplicable to the treatment of any mineral oil fraction containinghydrocarbons of any number of carbon atoms to the molecule with an acidwhich may comprise HzSOi, H3PO4, HCl, etc. Pentane-pentene andhexane-hexane fractions are very suitable for treatment by my processfor the selective absorption and removal of tertiary-base olefines(olefines capable of yielding tertiary alcohols upon hydrolysis).

A butane-butene fraction containing approximately 15 to 20% by weight oftertiary or gamma butylene is introduced at 30 while an equivalentamount of 65 to 70% H2804 is introduced at 29. To insure the completeabsorption and removal of the gamma butylene, about a 10% excess of 65to 70% H2804 is introduced at 29 (the amount of H2504 to be added beingcalculated on the amount of isobutylene to be absorbed). The vessel illin the meantime has been filled with 65 to 70% H2804 and thebutane-butene fraction to be treated, the exact proportion of thecontents of the vessel being dependent on the desired relative time ofcontact. The liquids flow in countercurrent fashion, the eiilux at 28comprising the butane-butane fraction from which the isobutylene hasbeen substantially removed while the efflux at 3| comprises H2504relatively saturated with isobutylene. The temperature is maintainedbetween about to F. to avoid substantial polymerization of the butene-land butene-2. The pressure in the vessel is approximately the vaporpressure of the butane-butene fraction at the operating temperature.

The apparatus assures ease of control, simplicity and flexibility ofoperation and maximum yield in the optimum minimum time of contact.

This application is a division of my application Serial No. 551,970,filed July 20, 1931, which issued April 3, 1934, 21511. S. Patent1,953,618.

It will be obvious that various substitutions in the materials treatedand in the liquids used, as well as modifications in the order andmanner of execution may be made in the practical. application of theinvention, but such substitutions and modifications are to' beconsidered as comprehended by the above disclosure and included withinthe purview of the following claims.

I claim as my invention: I

'1. An apparatus for the treatment of substanzone and the end zonescomprising separating compartments, each end zone containing an inletand an outlet for the liquids undergoing treatment, said communicatingzones being open for the free passage of fluid at a plurality of points,whose loci are at substantially opposite ends of a vertical axis drawnin the plane of a side of a zone.

2. An apparatus for the treatment of substantially immiscible fluidswhich comprises a vessel. a plurality of diaphragms dividing said vesselinto a plurality of treating zones arranged in contiguous relationship,each of the diaphragms being perforated at the upper and lower portionsof its periphery with openings of such a size that they permit liquid tocirculate between two communicating treating zones without causing theturbulence of a mixing zone to be communicated to a separating zone,said lower set of perforations being so arranged that removal of fluidfrom an end treating zone will cause automatic flow of fluid from allthe other treating zones to said end zone, and agitating means disposedin alternate treating zones, each end zone containing an inletand'outlet for the liquids undergoing treatment.

3. An apparatus for the treatment of substantially immiscible fluidswhich comprises a vessel, a plurality of diaphragms dividing said vesselinto a plurality of treating zones arranged in contiguous relationship,each of the diaphragms being perforated at the upper and lower portionsof its periphery with openings of such a size that they permit liquid tocirculate between two communicating treating zones without causing theturbulence of a mixing zone to be communicated to a separating zone,said lower set of perforations being so arranged that removal of fluidfrom an end treating zone will cause automatic flow of fluid from allthe other treating zones to said end zone guide vanes located on thewalls of the diaphragms, and agitating means disposed in alternatetreating zones, each end zone containing an inlet and outlet for theliquids undergoing treatment.

4. An apparatus for the treatment of substantially immiscible fluidswhich comprises a vessel, a plurality of diaphragms dividing said vesselinto a plurality of treating compartments arranged in contiguousrelationship, each of the 5 diaphragms being perforated at the upper andlower portions of its periphery with openings of such a size that theypermit liquid to circulate between two communicating treating zoneswithout causing the turbulence of a mixing zone 10 to be communicated toa separating zone, said lower set of perforations being So arranged thatremoval of fluid from an end treating zone will cause automatic flow offluid from all the other treating zones to said end zone, guide vaneslo- 16 cated on the walls of the diaphragms, a shaft disposed withinsaid vessel and eccentric with respect to the horizontal axis of saidvessel, and agitating means supported on said shaft and located withinalternate compartments, each end 20 compartment containing an inlet andoutlet for the liquids undergoing treatment.

5. An apparatus for the treatment of substantially immiscible fluidswhich comprises a series of substantially horizontally arrangedagitating 25 and settling compartments only the contiguous compartmentsof which are in communication with each other, agitating devices onlylocated in alternate compartments and inlet and outlet means containedin each end compartment, said 30 communicating compartments being openfor the free passage of fluid at a plurality of points whose loci are atsubstantially opposite ends of a vertical axis drawn in a plane of aside of a' compartment. 85

6. An apparatus for the treatment of substan-- tially immiscible fluidswhich comprises a series of agitating and settling zones, each agitatingzone being in communication with no more than two settling zones viaopenings of such size that 40 they permit liquid to circulate betweentwo zones without causing the turbulence of an agitating zone to becommunicated to a settling zone, said openings being so arranged thatremoval of fluid from an end treating zone will cause automatic flow offluid from all the other treating zones to said end zone, agitatingdevices located in altemate zones and inlet and outlet means containedin each end zone.

- GUSTAV A. KRAMER.

